cells :) Flashcards
where can we see prokaryotic cells and how complex are they?
seen in bacteria and archaea
very simple build-up
what are 2 main types of cells?
prokaryotic
eukaryotic
where can we see eukaryotic cells and how complex are they?
seen in organisms like animals, plants, fungi and protists
very complex build-up
what’s the most important difference between prokaryotes and eukaryotes?
the presence of membrane bound organelles and organized DNA molecules in eukaryotes and the lack of either in prokaryotes
describe what an organelle is
they are membrane bound structures that serve a specific purpose in the cells operation
where is the plasma membrane?
around the structure of the cell
what is the plasma membrane made out of?
a phospholipid bilayer
what the role of the protein attached molecules in the plasma membrane?
act as regulatory or sensory structures
what is the structure of the plasma membrane and how is it after referred as?
a fluid structure
often described as : fluid-mosaic structure
what’s the main purpose of the plasma membrane?
to contain the cells cytoplasm, organelles and regulate what enters and exits the cell.
what is the cytoplasm?
the ares that contains all other cell organelle except the nucleus.
what’s the membrane that contains the nucleus called ?
nucleoplasm
how would you describe the texture of the cytoplasm and what is it made of?
gelatinous substance made up of cytosol and is 80% water
what’s the use of the cytoplasm?
suspend the organelles
acts as a medium in which molecules and organelles can be transported
maintain the structure of the cell
What does the nucleus function as within the cell
It functions as the command center
What is the nucleus and where is it located?
Large organelle located near the center of the cell
What’s enclosed within the nucleus?
The DNA ( condensed as chromatin ) that contains the genetic info to all the cell’s processes
What’s the external membrane of the nucleus called?
The nuclear envelope
Where are nuclear pores located?
On the nuclear envelope ( external membrane of the nucleus)
What’s the function of nuclear pores?
To allow entry and exit to molecules from and to the nucleus
What is a structure within the nucleus?
neucleous
what’s the use of the neucleous?
production ribosomal RNA (rRNA)
the assembling of the 2 ribosomal subunits
expand the word SER
smooth endoplasmic reticulum
what is the endoplasmic reticulum and where is attached to?
a branching organelle attached to the exterior of the nucleus.
what is the ER made out of?
folded tunnel spaces called citernae
what are the tunnel like spaces in the ER’s used for?
as a transport system for the molecules produced within the organelle
how do u identify the RER from the SER?
by the ribosomes that are studded
what does the SER produce?
lipids and steroids.
what is the purpose of ribosomes?
producing the proteins required for the cell
what are ribosomes made out of?
rRNA and protein
what does the protein in the ribosomes do?
act as the site where protein synthesis occur
where do u find the ribosomes?
studded in the RER
and freely in the cytoplasm
polysomes?
groups of ribosomes making the same protein
Golgi apparatus, aka?
Golgi body
what’s the use of the Golgi apparatus?
acts as a packaging plant of of the cell. it takes molecules form the ER’s and alter/package them for distribution inside and outside the cell.
what are the packaged molecules bound by?
by a membrane called vesicle
what’s the membrane composition of the Golgi apparatus similar to?
the cell membrane, which allows fusion.
similarities between the Golgi apparatus and the ER’s?
similar shape
contain folds called cisternae
structure of vesicles?
small membrane bound sacks composed of phospholipid bilayer
what are vesicles used for?
to store and move the molecules within and towards the outside of the cell
4 types of vesicular structures?
vacuoles
lysosomes
transport vesicles
secretory vesicles
what is the function of vocules?
contain and store molecules (usually water)
what is the function of lysosomes?
contain digestive enzymes used in the breaking down of molecules
what is the function of secretary vesicles?
contain materials that needs to be excreted from the cell.
what’s use of the mitochondria?
create energy within the cell
how does the mitochondria create energy? and using what?
by cellular respiration
using oxygen and glucose to create ate, water and carbon dioxide as a waste product ( reverse of photosynthesis)
the mitochondria has _ layers of membrane. and the folded inner area is called_.
2
cristae
does mitochondria has the same DNA as the rest of the cell?
no
are all organelles bound in membrane?
yes
what is the cell membrane described as?
fluid mosaic
why is the cell membrane described as fluid mosaic?
fluid - cuz individual proteins and phospholipids can drift laterally
mosaic - cuz it has different proteins and other molecules that could be seen to resemble a mosaic
what’s the largest part of the bi-layer?
phospholipids
what is a glyco lipid similar to? and what’s the single difference?
a phospholipid
it has a carbohydrate chain attached to the polar head
what are glycoproteins?
proteins that have a carbohydrate chain bonded to them
describe what cholesterol is, it’s percentage in an average animal cell membrane and it’s use.
a steroid
that makes up to 30% of the animal cell
restrain movements of the phospholipids and hinders close packing
what are membrane proteins?
a general term for the other proteins that perform various functions needed for cell activity.
what are the five types of cells you would find in the cellular membrane?
phospholipids
glycolipids
glycoproteins
cholesterol
membrane proteins
what acts as identification tags in cells?
the carbohydrates attached to the glycolipids and glycoproteins
4 functions membrane proteins perform? ( be specific)
cell recognition- using carbohydrate chains
transport - channel and carrier proteins allowing molecules or ions to move across the bi-layer
reception- binds to molecules according to their shape and the binding acts as a signal
enzymatic activity - catazyles a specific reaction
how does cell recognition work?
using carbohydrate chains
membrane proteins that act as receptors (explain )
binds to molecules according to their shape and the binding acts as a signal
membrane proteins that transport (explain)
carrier and channel proteins allowing molecules or ions to move across the bi-layer
membrane proteins that allow enzymatic activity (explain )
catalyzes a specific reaction
most important function of the cell membrane
movement of molecules and ions through it
2 types of movement across membrane
passive ( no energy needed )
active ( requires energy)
3 types of passive transport?
diffusion
osmosis
facilitated transport
is diffusion fast or slow and how can we increase it’s rate?
slow
by increasing temperature and/or pressure
diffusion usually occur with what type of molecules?
lipids
soluble molecules
gases
alchohol
what is osmosis?
water moving across the membrane
what’s aqua-porous?
permeable ares of the membrane that are protein specific for water during osmosis
what is facilitated transport?
molecules that are transported across the membrane with the help of proteins ( usually cuz it’s too big)
2 types of facilitated transport proteins
channel
carrier
channel proteins act as a channel for _, like ___.
ions
sodium, potassium, chlorine
Can channel proteins open and close?
yes
carrier vs channel proteins
transport specific molecules
transport ions
carrier proteins usually transport?
fructose
glucose
galactose
nucleotides
amino acids
do carrier proteins use ATP?
no, cuz they are passive transport
why does active transport need energy and what is that energy?
cuz it goes against the concentration gradient
ATP
what types of molecules use active transport ?
large molecules
what happens in endocytosis?
the cell membrane formed a vesicle around the materials it wants to take in and merges with the vesicle.
phagocytosis, explain
the process by which large materials like other cells are take inside the cell by forming a vesicle around it. visible at lower magnification
pinocytosis, explain
large molecules are taken into the cell by forming a vesicle around it. visible at higher magnification
receptor mediated endocytosis, explain
receptors at the surface are triggered by a specific molecule to form vesicle around the said molecules.
which cells perform exocytosis?
hormones and digestive fluids
3 types of endocytosis?
phagocytosis
pinocytosis
receptor mediated endocytosis
ATP is produced in the body through?
Bio-chemical reactions
the formula for ATP production (simplified) ?
sugar and oxygen form water, ATP and CO2
3 stages by which we produce energy?
glycolysis
Krebs cycle
oxidative phosphorilation
Krebs cycles is a.k.a?
citric acid cycle
Tricarboxylic acid cycle
C6H12O6?
glucose
the carbohydrate when creating energy
C3H403?
Pyruvate
glucose after it’s been cleaved in 2
NADH?
nicotinamide adenine di-neucleotide
a co enzyme that acts as an electron carrier
FADH?
Flavin adenine di-neucleotide
a co enzyme that acts as an electron carrier
where does glycolysis occur?
in the cytosol of the cell
what happen during glycolysis?
convert glucose molecules into pyruvate to produce 2 ATP molecules
which of the 3 forms of energy production is anaerobic?
glycolysis
what does glycolysis produce?
2 ATP molecules
NADH
NADH is the reduced form of_
NADH+
NADH will be used mostly during which stage of energy production?
oxidative phosphorylation
Pyruvate is the _ form of _
oxidized form of acetyl
when will acetyl be mostly used in?
during the Krebs cycle
where does Krebs cycle take place?
within the mitochondria
what happens to Pyruvate during Krebs cycle?
pyruvate turn into many intermediates before eventually forming CO2 and H2O
what happens to NADH+ AND FADH+?
hydrogen is used to reduce them so they’ll carry electrons during oxidative phosphorylation
what does Krebs cycle produce?
ATP
NADH
FADH2
what’s the final stage of of cellular respiration?
oxidative phosphorylation
what are the 2 sub stages during oxidative phosphorylation?
electron transport chain stage
Chemiosmosis
what’s the matrix membrane of the mitochondria?
the innermost membrane
what does the oxidative phosphorylation use during electron transport chain stage to generate energy?
the proteins embedded within the matrix membrane of the mitochondria
what happens during electron transport chain stage ?
NADH and FADH2 carry electrons in a downhill manner where it ensured that the new stage is more electronegative than the last
this energy is used to pump hydrogen outside of the matrix to create a proton gradient, where concentration os higher outside the matrix than inside
what happens during chemiosmosis?
the hydrogen ions naturally move from their new place of high concentration to low concentration inside the matrix.
to do that, they have to go through a channel protein called “ATP synthase”
How dips ATP synthase create energy?
it acts as a turbine that is powered by the [assing hydrogen ions. as it “turns” it generates large amounts of ATP (32)
the final amount of ATP created through cellular respiration is around?
36 - 40
What is metabolism?
the sum of all chemical activities occurring inside a living cell.
